Question

密码是表示消息的秘密文本。在这个问题中，原始消息中的每个字符都由密码中的6个字符的字符串表示。例如，文本“java”由4个字符组成，在密码中表示为24个字符的字符串：

kjdktizldzaecvyrvwaaemgk

在这个问题中，您的任务是使用下面给出的方法decipherChar（String）来完成解码密码的方法解码（String）。

/**
 * This method decodes a 6-character input String into a single character.
 * The first and second halves of the input String are compared lexicographically.
 * The middle character of the smaller half is then returned.
 * In case of equal halves, a space character is returned.
 * 
 * @param inputStr The 6-character String to be decoded.
 * @return The decoded character.
 */ 
public static char decipherChar(String inputStr) {
     // implementation not shown here
}

说明

将参数密码作为要解码的密码。
检查密码是否有效。如果密码是空字符串，则返回字符串消息“no cipher”。如果密码的长度不能被6整除，则返回字符串消息“invalid cipher”。
如果密码有效，则使用给定方法decipherChar（String）将密码的每个6个字符的子串解码为原始消息的字符。 decipherChar（String）方法接受长度为6的String并返回解码后的字符。
连接所有已解码的字符并返回原始邮件。

Answer 1

String returnstring = "";

if(cipher.equals(""))
{
        return "no cipher";
}

if(cipher.length() %6!=0)
{
        return "invalid cipher";
}

if(cipher.length()==6)
{
        char A = decipherChar(cipher.substring(0,6));
        returnstring =  Character.toString(A);
}

if(cipher.length()==12)
{
        char A = decipherChar(cipher.substring(0,6));
        char B = decipherChar(cipher.substring(6,12));
        returnstring =  Character.toString(A) + Character.toString(B) ;
}

if(cipher.length()==18)
{
        char A = decipherChar(cipher.substring(0,6));
        char B = decipherChar(cipher.substring(6,12));
        char C = decipherChar(cipher.substring(12,18));
        returnstring =  Character.toString(A) + Character.toString(B) +
Character.toString(C);
}

if(cipher.length()==24)
{
        char A = decipherChar(cipher.substring(0,6));
        char B = decipherChar(cipher.substring(6,12));
        char C = decipherChar(cipher.substring(12,18));
        char D = decipherChar(cipher.substring(18,24));
        returnstring =  Character.toString(A) + Character.toString(B) +
Character.toString(C) + Character.toString(D);
}
return returnstring;

Answer 2

好吧，我会给你带来疑问的好处，并帮助你用一些代码来帮助你入门。并且可能会有一些错误，所以要小心......

public static String decipher(String cipher){

    String deciphered = null;

    //check if cipher is valid
    if(isValid(cipher)){
        char[] arrChar = new char[cipher.length()/6];
        for(int i = 0; i< cipher.length()/6; i++){
            String substring = cipher.substring(i, i+6);
            arrChar[i] = decipherChar(substring);

            //now you need to combine the array of char into a string.
        }
    }
    else{
        return  _msg;
    }

    return deciphered;
}

给定参数密码作为要解码的密码

2 个答案: